<!DOCTYPE html>
<html>
<head>
<title>四种边距:上、下、左、右</title>

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">

<link rel="stylesheet" href="2.css" type="text/css"></link>
</head>
<!-- 外边距的常用属性与内边距基本类似 -->
<body>
	<div class="container">
		<div class="bd">
			<div class="pd">
				<div class="content"><p>hello, world!</p></div>
			</div>
		</div>
	</div>
</body>
</html>
